Pass through window



Nov. 5, 1963 G. v. H. FREEMAN 3,109,535

PASS THROUGH WINDOW Filed Oct. 17. 1961 United States Patent C) 3,109,585 PASS THRGUGH WINDOW George Vivian H. Freeman, Los Altos, Calif., assignor to Litton Precision Products, Inc., San Carlos, Calif. Filed Oct. 17, 1961, Ser. No. 145,727

12 lairns. c1. 232-4) This invention relates to equipment useful in industrial plants where an extreme degree of purity of the products or of freedom from contamination must be observed. Processing or assembly areas fulfilling those requirements are frequently referred to. as White Rooms. More particularly, the invention is concerned with pass-through assemblies mounted through an aperture or window in a well separating two distinct work areas, at least one of which is a White Room in the meaning of the term as used above.

- As a typical example of an industrial plant layout including White Rooms as the processing and assembly area, those engaged in the manufacture of microwave tubes should be mentioned. Manufacturing facilities of this type are equipped with special ventilation systems including air purification equipment. Numerous other precautions are generally taken for preventing contamination of the product or components by contact with dustcarrying air or other sources of impurities. Frequently, distinct White Rooms are provided and separated from other work areas by walls. As mentioned above, at least one of the two rooms separated by the wall constitutes a White Room or Clean Area. Under certain circumstances, both rooms separated by the wall are maintained at different degrees of purification, with one distinguished from the other by the designations Clean Area and Super Clean Area.

Assuming that, by way of example, components of the product to be assembled are individually handled in one of the rooms which may be a clean processing area, and it is intended to assemble the components in another adjacent area in which a higher degree of purity must prevail, a passage must be provided for transferring the components from one area into the other undercontamination-protected conditions. the foregoing general discussion that this term designates conditions under which practically no impurity is transferred together with the component from one area or zone into the other. r

3,109,585 Patented Nov. 5, 1963 and an integral cover or moving closure member for the chamber. The cover is slidably mounted across the window so that it can selectively be shifted into different successive positions with respect to the two zones. The chamber has two openings, generally pointing in opposite directions, with one of the openings communicating with the space at one side of the wall and the other opening communicating with the space at the other side of the wall.

The cover or shield is dimensioned so that, when it is in an intermediate position,- it simultaneously closes both openings. In one of its extreme positions, the cover closes the chamber opening communicating with the space at one side of the Wall, while the chamber remains open toward the other side. Similarly, when in the opposite extreme position, conditions are reversed. It will be understood that, by employing one single cover mounted as described above, the chamber never communicates simultaneously with both sides of the wall and one of the primary requirements for this type of assembly is fulfilled.

In accordance with another feature of the invention, the cover is slidably mounted so that it can easily be shifted from one position into another. Further features of the invention include a pair of parallel side walls for the chamber, each side wall having a circular groove in its surface facing the other side wall, with the cover or shield having the shape of a half-cylinder and mounted between the side walls in such a manner that its circular edges slidably engage the grooves.

Still further features of this invention include a shelflike platform or receptacle forming the bottom of the chamber on which the objects to be passed through the window can be deposited by one operator from one side of the wall and removed, suitably by another operator, from the other side of the wall.

The novel features which are believed to be characteristic of the invention, both as to its organization and method or construction and operation, together with fur- It will be understood from ,Accordingly, it is one of the important objects of this invention to exclude the production of both dust producing elements and components which induce'the formation of spanks or other contamination hazards,

It is a further object of this invention to eliminate electrical and electronic components from pass-through windows for the purpose under consideration, in order to simplify the structure of pass-through windows, and elim- A inate the above mentioned drawbacks of such prior art venting connection. between the areas or zones to be sep-.

arated from each other, so that any possibility of inadvertently handling the window doors in an :incorrect manner is excluded.

A still further object of the invention is the, provision of a relatively inexpensive pass-through window assembly without sacrificing the highjdegree of safety achieved with prior art arrangements.

ther objects and. advantages thereof, will be better understood from the. followingdescription considered in connection with the accompanying drawing in which an illustrative embodiment of the invention is disclosed, by way of example. it is to be expressly understood, however, that the drawing is for thepurpose of illustration and description only and does not constitute a limitation of the invention.

In the drawing:

FIG. 1 is a front view of one embodiment of the invention,

.FIG. 2 is across sectional view along the line 2-2. of FIG. 1; and

FIG. 3 is an isometric view of the assembly of FIGS. 1 and 2.

Identical elements are designated by the same reference numerals throughout the figures.

In the drawings, the wall separating two diiferent zones or work areas from each other is shown in a front view,

partially broken away, in FIGS. 1 and 3, and in section in FIG. 2;. it is designated by reference numeral 10 in all three figures. A chamber receiving the objects to be passed through a rectangular cut-out or window in the Wall is formed by a pair of circularside walls 12 and 14,

made for example from aluminum or any other suitable material. Bothside walls are connected to each other by a T-shaped supporting assembly or shelf composed of arhorizontally extending platform 16 anda vertically arranged plate 18 forming the stem of the T. The por- Accordingly, and in accordance with an important feawhich are separated by a wall having a window through it, includes a chamber which extends through the window,

tions of the shelf are maintained in their positions with respect to each other by two pairs of brackets, with brackets 20 and 22 positioned at one side of plate 18 and another pair of brackets at the other side of the plate;

one of the second pair, bracket 24, is shown in FIG. 2.

or in any other suitable manner. Considering the necessity to maintain the entire assembly free from dust or any other impurity, it has been found advantageous to form the platform 16 and the plate 18 from plywood coated with a thin layer of chemically resistant synthetic material such as that known'under the trade name Formica. Each of the circular side walls 12 and 1 4 is provided with a circular groove in its inner surface facing the other side wall. Thus, groove 28 formed in the side wall 12 faces side wall 14, and groove 30 formed in side wall'14 faces the side wall 12. As shown in FIG. 2, the grooves terminate at locations adjacent the vertical supporting plate 18, in order to avoid formation of a channel of communication between the zones which must remain separated from each other. Such terminal locations 32 and 34 of groove 28 appear in FIG. 2.

A cylindrically curved cover or shield 36 is mounted between the faceplates 12. and 14 in such a manner that its circular edges slidably engage the grooves 28 and 3t).

Suitably, the cover is formed from transparent plastic material such as that commercially available under the name of Lucite. In order to facilitate handling the cover, each of its straight edges may be provided with an outwardly bent portion 38 and 40, each of them forming a handle which remains positioned at the same side of the wall 10, regardless of the position of the cover 36. As best shown in FIG. 2, the cylindrically curved shield or cover extends through an arc of at least 180 angular degrees so that, when in its intermediate position as shown in FIG. 2, it forms a dome-like enclosure above platform 16 which is then entirely separated from both zones at opposite sides of the-wall 10.

In order to provide an improved sealing effect between the cover and the other components involved, sealing strips formed from rubber or the like may be used. One such sealingstrip maybe secured to the upper portion of the opening through wall it is designated by reference numeral 42. Twofurther strips 44 and 46 are suitably provided each along one of the edges of platform 16 to'engagethe inner surface of cover 36.

-'In operation, and under the assumption that an object such as an assembly component must be transferred from the left-hand side of FIG. 2 to'the right-hand side of FIG. 2, an. operator shifts the cover 36 from its position shown in FIG. 2 into the position shown in FIG. 3. This is accomplished by imparting to the cover a rotating movement'during which the cover edges slide within the grooves 28 and 30, and using handle 38. It will be apparent that, with the cover assuming all of the intermediate positions, the half cylindrical chamber space remains separated from the right-hand zone of FIG. 2

inserted between the surfaces of during this entire operation. Subsequently, the operator deposits the object to be transferred on the platform 16. The next step includes rotating the cover in the opposite direction. which rotational movement, at first, returns it into the position shown in FIG. 2. At this movement the chamber is again separated from both zones. Then, a continuing rotational movementof the sliding cover 36 results inthe inverse position with the chamber being opened toward the right-hand side 'of FIG. 2, but remaining closed toward the left-hand side. In this position, the object may be removed from the platform; It will beapparent that the entire process, regardless of the sequence of steps; excludes any position of the cover in V which the zones at opposite sides of thewall communi- The cover can be shifted in cate through the chamber. position from either side'of the wall by the use of handle 38 or 40. The, use of transparent material such as Lucite for the cover permits the operators at opposite sides of the wall to recognize and to observe eachother. 7

As shown in FIGS. 1 and 3, the entire assembly described above may be secured in a window-like opening through the wall 10' by means of angularstrips 48 and objects on the platform 16 .0 using screws 52, with'another pair of such angular hand, the angular extent of the cover should not signifi- I cantly exceed this angle.

It will be apparent that, at an angle of 270, even whenin an extreme position, the cover would separate the chamber from bothzones in all possible positions. Referring to the embodiment shown in the drawing employing a flat platform 16, an are covering about 210 has been found suitable. However, and in order to mention one of the many possible modifications, the platform 16 may have a V-shaped cross'section which configuration may be preferred for transferring small components. Then a smaller'angle of the cover is sufficient, and it will be understood that the desired effect is achieved when the cover -is dimensioned to extend over an angle sufliciently great to simul tion, but sufficiently small to leave one of the openings open when in an extreme position.

As a consequence of the sliding movement of the cover, it is shifted from the zone at one side of the wall into that at the other side of the wall. 'When positioned substantially in one zone, the cover separates the chamber exclusively from that zone and, when assuming an intermediate position, it simultaneously separates the chamber from both zones.

In the foregoing description, possible additional techniques for improving the sealing effect between the two zones to be separated have been omitted. By way of example, the grooves 28 and 30 may be linedwith any of the entire arrangement. Platform 16 and supporting plate 18 may be glued or otherwise secured to the side' walls 12 and 14, with sealing and packing material being contact, to prevent contamination. 3

It is to be understood that the above-described arrangemen-ts are illustrative of the application of the principles of the invention. Numerous others'arrangements may be devised by those skilled in the ant without departing from the spirit and scope of the invention. Thus, by way of example and not of limitation, the sidewalls may have a shape different from that shown and described. The cover or shield maybe mounted to permit 1 a swivel movement about pivots instead of sliding in grooves. A moving closure'member composedof, for

example, a number of parallel elements joined to each other such as those used with desks may be employed.

When such a structure is employed, however, it is to be i understood that the closure forms one unit so that raising one side necessarily lowers the other side.

with a fiat platform 16,'in which case the grooves remain open to continue to the straight side Wall edges, so that the cover protrudes from the grooves and from the space between the side walls when moved toward its extreme positions. Furthermore, the entire assembly may be mounted in the wall window in a position rotated by 90 or 180. 'In the first case, one of the side walls 12 or 14 actually becomes the bottom of the chamber.

When-mounting the assembly reversed by 180, the platform 16 forms a roof for the chamber, and the objects to be transferred are deposited in the cylindrical container form-ed by the cover itself. In the embodiment shown and described, the vertically arranged supporting plate 18 'is shown as forming part of the prefabricated assembly which is subsequently mounted in the windowthrough If desired, the

If desired, half-circular side walls may be used in conjunction shown, with a pair of vertically, downwardly extending slots for accommodating the lower part of the circular side walls 12 and 14. Then, the vertical supporting plate 18 in FIG. 2 is substituted by a portion of wall 10, between such slots. Generally speaking, the shelf assembly, the cover and the chamber may be modified with respect to their dimensions and proportions to suit any specific purpose.

Accordingly, from the foregoing remarks, it is to be understood that the present invention is to be limited only by the spirit and scope of the appended claims.

What is claimed is:

1. In a contamination-protected pass-through assembly for interconnecting two zones separated by a wall having a window through it, a chamber having a bottom and two side walls facing each other, said bottom and side walls being fixedly secured to the wall and mounted to extend from one zone through the window into the other zone, the chamber having one opening into each of the zones, each of the side walls having a peripheral groove provided in its surface facing the other side wall, and a cover slidably engaging both grooves for selectively shifting it from one zone into the other zone to assume extreme and intermediate positions with respect to said bottom, the cover simultaneously closing both openings when in an intermediate position, with one opening being closed and the other opening remaining uncovered when the cover assumes an extreme position.

2. In a contamination-proof pass-through assembly for interconnecting two zones separated by a wall having a window through it, a chamber having a bottom and two side walls facing each other, said botton and side walls being fixedly secured to the wall and mounted to extend from one zone through the window into the other zone, the chamber having one opening into each of the zones, each of the side Walls having a peripheral circular groove, a cylindrically curved shield for the chamber having two circular edges slidably mounted between the sidewalls, with each edge engaging one of the grooves, to permit selectively shifting the shield by rotation from one zone into the other to assume an intermediate position and two extreme positions with respect to said bottom, the shield being dimensioned to simultaneously cover both openings when in an intermediate position, the shield covering only one opening when in any of both extreme positions, with the other opening remaining uncovered.

3. In a contamination-protected pass-through assembly, a wall separating first and second zones and having a window through it, a fixed shelf-like support extending across and secured to the window, a pair of side panels also extending across the window with one panel being positioned at each side of the support, said support and side walls forming a stationary passageway through the window, an integral cover engaging the side walls, the support and the window, and means for movably mounting the cover to assume central and two extreme positions with respect to said passageway, the cover separating the passageway from both the first and second zone when in its central position, and the cover separating one of the zones from the passageway with the passageway remaining open toward the other zone when assuming any of the extreme positions.

4. In a contamination-protected pass-through assembly, first and second zones separated by a wall having an opening through it, a chamber including a fixed shelflike support forming a stationary bottom for said chamber extending through and secured to the opening, and an integral cover for the chamber slidably mounted across the opening for selectively shifting it into different successive intermedite and extreme positions with respect to said support between the first and second zone, with the cover separatnig the chamber exclusively from one of the zones when shifted into the extreme position within said zone, the cover simultaneously separating the chamher from both zones when assuming an intermediate position, and said fixed shelf-like support being permanently maintained in a stationary position in which it extends from one into the other zone.

5. An assembly for passing objects from one zone through a window in a separating wall into another zone under protective conditions against contamination caused by transfer of foreign matter and air, comprising a chamber including a fixed shelf-like support forming a stationary bottom for said chamber adapted to be fixedly mounted in the window, with said fixed shelf-like support being permanently maintained in a stationary position in which it extends from one into the other zone, and an integral cover for the chamber slidably mounted across the window for selectively shifting it into different successive intermediate and extreme positions between the first and second zone, with the cover separating the chamber exclusively from one of the zones when shifted into the extreme position within said zone, the cover simultaneously separating the chamber from both zones when assuming an intermediate position.

6. In a contamination-proof pass-through assembly interconnecting first and second zones separated one from another by a wall, stationary means including a fixed shelf-like support defining a thrid zone between the first and second zones and extending through an aperture in the wall, the third zone having an opening into the first zone and another opening into the second zone, and a slidable cover mounted for selectively shifting it from one zone into the other zone to assume extreme and intermediate positions, the cover simultaneously closing both openings when in an intermediate position, and the cover closing only one opening when in an extreme position.

7. In a contamination-proof pass-through assembly interconnecting first and second zones separated one from another by a wall, stationary means including a fixed shelflike support defining a third zone between the first and second zone and extending through an aperture in the wall, the third zone having an opening of a predetenmined angular extent into the first zone and another opening of substantially the same angular extent into the second zone, said support forming a'bottom for the third zone, and a unitary cylindrical shield pivotally mounted above said support to swing between the first and second zones, the angular extent of the shield being equal to at least twice that of each opening to simultaneously close both openings and to separate the third zone from the other zones when the shield assumes a central position, with only one of the openings being uncovered when the shield is pivoted into one of the first and second zones.

8. In a contamination-protected pass-through assembly interconnecting two zones separated by a wall having a window through it, a chamber having a fixed shelf-like support forming the bottom for the chamber and two side walls facing each other mounted to extend from one zone through the window into the other zone, the chamber having one opening into each of the zones, a cover shaped for simultaneously closing both openings, and means for shifting the cover from one into the other zone for uncovering one of the openings, with the other opening remaining closed.

9. In a contamination-protected pass-through assembly, a wall having a window in it for interconnecting two zones separated by the wall, a chamber forming one opening into each of the zones and having a fixed bottom serving as a stationary receiving platform for objects to be passed through the window, the chamber having also a pair of vertical side walls facing each other, the bottom being secured to the side walls along a horizontally extending diameter to divide each side wall into an upper and lower half-circle, each side wall having a circular peripheral groove in its surface facing the other side wall, the grooves extending over the entire upper half-circle of the side walls and also into the lower half-circle, a cylindrically curved cover for the chamber having two circular edges slidably mounted between the side walls, with each intermediate and extreme positions, the cover being ditnensioned to simultaneously close both openings when in an intermediate posit-ion and positioned substantially between the upper 'halves of the side Walls, with about each half of the cover extending into one of the zones, the cover covering only one opening in one zone with the remainder of the'coveribeing positioned between the lower halves of the sidewalls in the same zone when in one of the extreme positions.

10. Ina contamination-protected pass-through assembly, a flat rectangular platform and a plate-shaped support for the platform secured to it along a centerline of the rectangle to form a shelf having a T-shaped cross section, a pair of parallel circular sidewalls for the shelf with each of one pair of parallel edges of the platform being secured to one sidewall along a diameter, the supporting plate being secured to each of the circular side walls along a radius forming a substantially right angle with the diameter, whereby the T-shaped shelf is secured in a position between the parallel circular side walls, a peripheral circular groove in each of the inner side wall surfaces, a cylindrically curved shield slidably mounted between the side walls with each of its circular edges engaging one of the,

grooves, the cylindrically curved shield having an extent to cover an angular space of at least 180 between the side walls so that it can assume a position in which it forms a dome-like cover above an entirely closed chamber having the shape of a half-cylinder between itself and the platform, the extent of the shield being substantially less than 270, so that a lateral portion of the half-cylindrical space is, opened when the shield is rotated into another position, and means for mounting the assembly, which includes the shelf, the side walls and the shield, in a Window through a wall, with the plate-shaped support being substantially aligned with the wall and the half-cylindrical chamber protruding at both sides of the wall.

11. In a contamination-protected pass-through assembly for interconnecting two zones separated by a wall having a window through it, a stationary shelf fixedly mounted horizontally across said window, said shelf having two parallel straight edges, each of said edges protruding at either side of said window, and a substantially half-cylindrical cover mounted for rotation about a horizontal axis to pivot by substantially the same maximum angular displacement in either direction toward either side of said wall and between extreme positions, with the half-cylindrical inner surface of said cover sliding along respectively different of said edges of said shelf for the different directions of rotation, the circular edges of said cover describing circular paths of suflicient maximu-rn angular extent that the cover forms a dome-like enclosure for said shelf when assuming a position intermediate said extreme positions, said shelf being accessible from only one side of said wall when the cover assumes the opposite of its two extreme positions.

12. In a contamination-protected pass-through assembly for interconnecting two zones separated'by a wall having a window through it, a chamber of generally cylindrical configuration, a cover for said chamber having a corresponding shape, a stationary shelf mounted within the chamber, the line between the ends of the shelf defining a chord intersecting the circle representing the cross section of said cylindrical configuration, and means for mounting said cover for movement beyond the shelf in both directions along said cylindrical configuration to selectively close said chambertoward one side of the window when the chamber is open toward the other side of the Window.

References Cited in the tile of this patent UNITED STATES PATENTS 2,550,998 Hilliker May 1, 1951 3,021,051 Day Feb. 13, 1962 FOREIGN PATENTS 152,197 Great Britain Oct. 14, 1920 316,815 Great Britain Aug. 8, 1929 715,318 France Sept. 22, 1931 

7. IN A CONTAMINATION-PROOF PASS-THROUGH ASSEMBLY INTERCONNECTING FIRST AND SECOND ZONES SEPARATED ONE FROM ANOTHER BY A WALL, STATIONARY MEANS INCLUDING A FIXED SHELFLIKE SUPPORT DEFINING A THIRD ZONE BETWEEN THE FIRST AND SECOND ZONE AND EXTENDING THROUGH AN APERTURE IN THE WALL, THE THIRD ZONE HAVING AN OPENING OF A PREDETERMINED ANGULAR EXTENT INTO THE FIRST ZONE AND ANOTHER OPENING OF SUBSTANTIALLY THE SAME ANGULAR EXTENT INTO THE SECOND ZONE, SAID SUPPORT FORMING A BOTTOM FOR THE THIRD ZONE, AND A UNITARY CYLINDRICAL SHIELD PIVOTALLY MOUNTED ABOVE SAID SUPPORT TO SWING BETWEEN THE FIRST AND SECOND ZONES, THE ANGULAR EXTENT OF THE SHIELD BEING EQUAL TO AT LEAST TWICE THAT OF EACH OPENING TO SIMULTANEOUSLY CLOSE BOTH OPENINGS AND TO SEPARATE THE THIRD ZONE FROM THE OTHER ZONES WHEN THE SHIELD ASSUMES A CENTRAL POSITION, WITH ONLY ONE OF THE OPENINGS BEING UNCOVERED WHEN THE SHIELD IS PIVOTED INTO ONE OF THE FIRST AND SECOND ZONES. 